A superjunction device, which often is also referred to as compensation device, includes a drift region with at least one region of a first doping type (conductivity type) and at least one second region of a second doping type (conductivity type) complementary to the first doping type. In some publications, the at least one first doping type region is referred to as drift region and the at least one second doping type region is referred to as compensation region.
A superjunction device may include a plurality of transistor cells, with each transistor cell including a first doping type region or a section of a first doping type region and a second doping type region or a section of a second doping type region. “The pitch” of a superjunction device is the center distance between two neighboring first doping type regions or two neighboring second doping type regions. The specific on-resistance RON·A of a transistor device is given by the on-resistance multiplied with the area of a semiconductor body in which the transistor device is implemented. One way to increase the specific on-resistance is to increase the number of transistor cells per unit area. Increasing the number of transistor cells is equivalent to reducing the pitch.
There is therefore a need for a method for producing a drift region of a superjunction device with a low pitch.